Friday, 21 December 2012

Cryophobic bees mean no Christmas berries at Kew

What's wrong with this picture? Lovely glossy leaves. A fringe of white variegation (if you like that kind of thing). Looks healthy enough, but where are the berries?

This is Holly, Ilex, and this is Christmas (or just about). And there are almost no Christmas berries to be seen from Holly Walk.

Holly Walk is one kilometre long, flanked by perhaps the world's most diverse collection of mature holly trees. There are lots of cultivars of the local native Ilex aquifolia and a selection of the other 500 or so species of Ilex. The oldest are 135 years old and in a typical year you can enjoy black, white and classic red berries from autumn through to winter. These are a couple of pictures from last year.

Holly Walk is part of my usual morning walk through Kew Gardens. It tracks what used to be called Love Lane, a carriage way between the two Royal estates that George II combined in 1802 to create most of what is Kew Gardens today. The hollies were first planted during Sir Jospeh Hooker's time as Director in the late nineteenth century.

I asked Tony Kirkham, Head of Kew's Arboretum, for his take on the berry-less Christmas. A poor spring, he said. It was cold and wet from April to mid-May, when the Ilex were flowering. It wasn't that the flowers themselves didn't like the miserable spring but it seems their insect pollinators were less than impressed. Bees in particular are vital for the cross pollination of Holly flowers and this year there just weren't enough of them.

This year none of the trees and shrubs at Kew are producing good fruit, unlike last winter when I was excitedly discovering my new botanic garden fructify. The BBC reported back in May that native bumblebees could cope but "the honeybee is just not designed to live with such weather extremes". A miserable spring means miserable honeybees. Miserable honeybees means substandard pollination and a miserable crop of holly berries.

An upside, perhaps, is a less than miserable winter. The folk lore is that a bountiful crop of holly fruit heralds a tough winter. Miserably cold winters have been correlated, at least by The Telegraph, with abundant berries. So this year we should be in for a most pleasant season, albeit with less colour. On that front, Tony notes, thankfully we planted more autumn colchicums (Colchicum autumnale) under the hollies this year.